feat: implement more of playback and reply flow

js/src/features/playback/particle-renderer.tsx

@@ -6,6 +6,7 @@ import { usePlaybackStore } from "@/stores/playback-store";
 import { MediaParticleView } from "./media-particle-view";
 import { TextParticleView } from "./text-particle-view";
 import { FallbackParticleView } from "./fallback-particle-view";
+import { AckButton } from "./ack-button";
 
 interface ParticleRendererProps {
   particle: StreamParticle;
@@ -53,6 +54,9 @@ export function ParticleRenderer({
       onClick={handleClick}
     >
       {renderContent()}
+      <div className="absolute right-4 bottom-16">
+        <AckButton particleId={particle.id} acks={particle.acks} />
+      </div>
     </div>
   );
 }